There has conventionally been used a touch panel of an analog resistance film form in electronic diaries, personal computers, etc. In the touch panel, as shown in FIG. 9, a touch side panel 101 with flexibility and a base side panel 102 are faced to each other via an insulating spacer 103. The above panels have transparent electrodes 112, 122 and pairs of parallel lead electrodes (named also as bus bars) 113, 114, 123, 124 set to respective one faces of transparent insulating base members 111, 121, and moreover the lead electrodes 113, 114, 123, 124 being disposed in a rectangular arrangement with the lead electrodes of both the panels in a state with the transparent electrodes 112, 122 being placed inside. Either one of the touch side panel and the base side panel has the transparent electrode set to the entire face of the transparent insulating base member thereon, whereas the other has the transparent electrode set to a part of the transparent insulating base member thereon while independent connection electrodes 115, 116 are mounted at insulating parts other than the transparent electrode so as to connect the independent connection electrodes by conductive adhesives 105 to the lead electrodes of the counterpart panel. In FIGS. 9 and 10, reference numeral 104 denotes a dot-shaped spacer, 131 a space part, 132 and 133 through hole parts, and 153 a binder.
The conductive adhesives 105 is a commercially available one such as obtained by dispersing a conductive filler 154 of flakes or spheres of a particle size of 1-20 μm or short fibers of a length of 1-20 μm, or the like, which is applied by a dispenser or the like. A heat treatment or the like is carried out in conformity with a set condition of a resin as a binder of the conductive adhesive 105 after the touch side panel 101 is bonded to the base side panel 102.
In the prior art, an out gas generated from a volatile solvent of the conductive adhesive 105 at the time of setting the conductive adhesive has caused lifting between the lead electrodes 123, 124 and the conductive adhesive 105 and/or between the connection electrodes 115, 116 and the conductive adhesive 105, or a stress of thermal expansion or thermal shrinkage of the touch side panel 101 and base side panel 102 at an environment resistance test has caused similar lifting, leading in some cases to a continuity failure because of a void 170 defined by the lifting (referring to FIG. 10). Especially, when a center part of the touch panel is pressed by a pen or finger, an upward force tends to generate at edges of the touch panel, thus easily causing lifting between the lead electrodes 123, 124 and the conductive adhesive 105 and/or between the connection electrodes 115, 116 and the conductive adhesive 105. Moreover, the materials of the touch side panel and the base side panel are a film and a glass different from each other, easily causing a stress of thermal expansion, thermal shrinkage of the touch side panel 101 and base side panel 102.